Simplify the following expression: $k = \dfrac{3cb + 3b^2}{4ab} + \dfrac{2cb - 4ab}{4ab}$ You can assume $a,b,c \neq 0$.
Solution: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{3cb + 3b^2 + 2cb - 4ab}{4ab}$ $k = \dfrac{5cb + 3b^2 - 4ab}{4ab}$ The numerator and denominator have a common factor of $b$, so we can simplify $k = \dfrac{5c + 3b - 4a}{4a}$